Breastmilk pumps are well known and generally comprise a hood body or breast shield that fits over the breast, a vacuum pump connected to the hood body for generating an intermittent reduced pressure or vacuum within the hood body, and a receptacle for the expressed milk. Examples of these pumps are shown in U.S. Pat. No. 4,857,051 and U.S. Pat. No. 4,964,851.
An aspect of the design of a manually driven pump has been the amount of effort required to use the pump. As the user's hand tired, the suction created may decrease, as well as the stroke rate, thus decreasing the effectiveness of the pumping action. Manufacturing costs have also been a consideration because of numerous pieces that may be required in the construction of these pumps. Regulating the vacuum pressure created by the pumping action is also a consumer design consideration. Solutions to these problems are presented in this invention as are other innovations.